Telephone system



Feb. 16, 1937. F LUBBERGER 2,070,909

TELEPHONE SYSTEM Fil ed Feb. '7, 1935 3 Sheets-Sheet l MM MAY. MAS NW1 MA1 MAZ MA3 INVENTOR.

FRITZ ,LUBBERGER ATTORNEY.

Feb. 16, 1937. LUBBERGER 2,070,909

TELEPHONE SYSTEM Filed Feb. 7, 1955 3 Sheets-Sheet 2 20p LW1 W1 T l I 4 1 11 --E!'' 52y INVENTOR.

FRITZ LUB BERGER &% Z 42% ATTORNEY.

Feb, 16, 1937. F. LUBBERGER V 2,070,909

TELEPHONE SYSTEM Filed Feb. 7, 1935 a sneezs-she t's FlG.3a

L y L z m '1 95. bra: pr kw 401- 4.14- 101. Li

J INVENTOR.

FRITZ LUBBERGER ATTORNEY.

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Patented Feb. 16, 1937 STATS ATENT OFFICE TELEPHONE SYSTEM Application February '7, 1935, Serial No. 5,343 In Germany February 13, 1934 6 Claims.

In telephone systems with automatic operation the establishment of a connection with a free line of a group of lines leading in the same direction is generally ,eiiected by a selector located in the speaking route so arranged that it automatically selects a free line from an outgoing group of lines leading in the desired direction, for example to another exchange. Since, except for comparatively rare exceptions, the lines are numbered consecutively, they are also connected consecutively to the sets of contacts in the banks of the selector, particularly the final selector. Difiiculties of operation arise, however, if number of outgoing lines in a particular direction, for instance the lines leading to one private branch subscriber, have to be increased or reduced. For commercial reasons, it is only possible in the most isolated cases to give the subscriber a new call number when altering the number of his lines. On the other hand it is also undesirable to connect up the newly required lines to another group of switches, since then when the num her is called and is found to be busy the completion of the connection to a free line, which is reached over quite another group of lines, can only be carried out by the provisions of auxiliary devices which seriously complicate the whole installation. It has therefore been proposed, to enable an increase in the number of lines to be made, to out the bank multiple, which however, has the disadvantage that there is then no longer any through multiple field, and with this arrangement if the number of lines is to be reduced it is necessary to connect up the multiple again in order to permit the calling subscriber to have access to all the lines of the group.

In order to permit the multiple capacity of an exchange having a given number of selecting stages, to be utilized as fully as possible when it includes a large number of line groups extending in different directions, it has also been proposed to reach these line groups over parallel or succeeding switches. With known arrangements of this kind, however, the multiple field of the switch, for instance the final selector, by the setting of which a calling party obtains connection with the desired line group, cannot be connected straight through but for each group of outgoing lines a single non-multipled contact must be provided in each impulse receiver over which either a succeeding selector associated with the impulse receiver is reached or a characterizing relay is operated by means of which the connection can be set up with a free line of a desired group over a parallel switch. If only a single group of lines can be reached over the parallel switch it will naturally follow that this switch can be started up to select a free line without the intermediate connection of a special group characterizing relay. These arrangements also possess the disadvantage that the multiple field needs to be altered when an individual subscriber becomes a P. B. X. subscriber or vice versa.

The object of the present invention is to produce an arrangement which ensures that in one instance the multiple capacity given by the number of numerical selecting switches is utilized as far as possible, and in the other instance the selectors at the switching stages over which the various groups of lines leading in the same direction are reached, may have a straightforward multiply connected contact field so that in the event of an alteration, particularly an increase in the number of lines extending in the various traffic directions (P. B. X. lines), operations on the straight forward multiple field shall be avoided, and particularly the cutting of the multiple and the connecting up of non-multipled individual characterizing lines to the various positions in the contact field. This is accomplished by the employment of a multiply connecting characterizing line associated with a group of lines leading in the same direction, together with a call allotter arranged so that after the seizure of the characterizing line which is accessible over all the speaking route switches of the group and is therefore multiply connected, a connecting path is set up under the control of a call allotter which is common to the group of speaking route switches with a free line of a desired group of an auxiliary switch, for example, a succeeding switch or a parallel switch, associated with the speaking route switch which has. been used. If succeeding switches are employed, preferably a succeeding switch or a set of succeeding switches is accessible over a non-multipled contact of the speaking route switch which is located beyond the contact groups. In the case of switches with motion in a plurality of directions (vertical and rotary switches) this succeeding switch or set of succeeding switches is preferably reached over a contact located at the end of each level. It is not necessary that the switching contact for the succeeding switches should actually be the last in the contact bank as this is generally used for other purposes, for instance statistical purposes.

Figs. 1-3 show embodiments of the invention.

Fig. 1 shows in principle the arrangement according to the invention applied to an installaion with succeeding switches;

ing path is set up with a free line of the desired group under the control of the allotter VO over a succeeding switch NWI associated with; thefinal selector LWI which has been employed. After the setting of the final selector "LWI on the characterizing line which marks the group.

of P. B. X. lines MAI, the allotter V is set into engagement with the final selectorLWI,

that the succeeding switch NWI sets itself on to a free'one of thelines=MAI. Aftertl'iis setting the allotte'r V0 initiates afurthermovement of the final-selector LW'I' to "an overflow position over which' the succeeding switch'NWI is accessible.-- It"--is '-quite-+immaterial for the purpose of the invention how'the finalselector LWI is constructed 'andthe particular position of the final selector over which thesucceeding switch'NWI is reached. ThefinalselectorLWI is 'shown-as-a rotary switch=with a plurality of contact groups which rotates until it'reaches-the overflow position over which the' succeeding switch NWI is accessible:

The'final selector LWZinFig; 1 is also a rotary H svn'tch -with'-a plurality of groups of contacts but-in-this-casethe-succeeding switch NW2 is connected to" normal contacts provided between the individual groups 'so that afterthe succeed ing'jswitch NW2has been set on'to'a-free 1ine "in'the 'desired-PZB. XI group; the final selector LWZhas onlyto move to the next normal positlOIILtOIWhiCh' the succeeding switchNW2 is con-- nected.

The finalselector'LW3 in Fig. 1 is avertical and rotary "switch and in this-case the succeedingswitch" is reached over the 'multiply-connected overflow contacts of the-individual levels.

The individual PiB X. line groups are connected 'to'the succeeding switch LWI accessible- -over the .final selectoriNWI and'to the succeeding switch'LW2 over the final selector NW2 of the individual-lines and can be connected up'as desired. either successively 'or' interspersed: The succeeding, switch NW3 whichis reached over the finalselector LW3 is divided into -three individual switches over each of which a "groupof' P. B.- XI .lines is accessible.

In accordance with Fig. 2 after the setting of the. .firial "sele'ctorLWI' on to the multiply connectedjcliaracterizing iline andithe energization of.' the .mark'ing, relay of the desired grouppf P.-B.. X. lines,..an-allotter .VO. is likewise set on to the final selector in use... The. group .ofP. B. X..

lines on towhich the parallel switch, e..g.; the switch PWI is. to be set is marked bythemarking.

relay. After the setting. of: the. parallel switch.

on..to:a free line--of the desired-group the connectionr'isrcompleted between the parallel switch and the.=connecting.path to.,the final selector.

Fig.1 3- ?shows 'annarrangement in..full; detail. After" thesetting of the final selectorLWI, which is in the-form of avertical and rotary switch, on to "the" multiply "connected" characterizing lines a I, 2, and 3, the allotter-Vois set-ont0 t final The marking of the lines MAI is efiectedby the relay BZI energized over the characterizing line so selector LWI. The marking relay BZ3 is operated over the characterizing line 2 and marks the group of P. B. X. lines to which the lines SA3I and SA32 belong; thereupon the succeeding switch NW sets itself on to a free line of the P. B. X. group whereupon over wiper a of the I allotter VO a starting circuit is completed for setting the final selector LW on to the overflow contact II.

If a calling subscriber desires a connection with the group of P. B. X. lines SA3 (lines SA3I, SAEZ), the seizing relay C is energized from a preceding selector on the seizure of the final selector LWI. In order to set the final selector LWI to the required level the relay A is energized by impulses sent by the preceding switch and operates the vertical magnet, (not shown), in the-usual manner. The off normal contacts of theswitoh are operated on the first vertical step and contact 2k is closed. During the opera tion of the vertical magnet, (not shown), relay V is energized and releases atthe end of the impulse series. Tlie following circuit is then completed for relay U: earth, contacts 27c, 31;, 4o, shaft contact 5w, winding I of relay U, battery, earth. Relay U prepares a circuit for the rotary magnet DLWI of the final selector LWI by closing the contact 611;. In-response -to the further impulses sent out by the subscriber, relay A is again energized and the rotary magnet DLWI is operated over: earth, contact Ia, relay V, contacts 6a, 8p, rotary magnet DLWI, battery, earth. By means of the rotary magnet DLWI the final selector. LWI is set on to the desired contact over which the multiply connected characterizing lines I, 2, and '3 are accessible. During the operation of the rotary-magnet DLWI relay V is'energized. As soonas the final-selector LWI takes its first step, the shaft'contact 5w is opened and hence the energizing circuit over winding I of the relay U is interrupted. Relay U, however, remains energized during the impulse series over: earth, contacts Iflc, IIv, IZu, winding II of relay U, battery, earth. After the setting of the final selector LWI has been completed relays U and V are released, first the relay'V and shortly afterwards the relay U owing to the opening of contact IIv. With relay V deenergized and relay U still energized the following test circuit is completed: earth, contacts-I30, I41), I5u, windings Iand II of relay P, lead.I5, relay G, wiper f of the succeeding switch NW in position 0, lead It, wiper c of the finalselector LWI on line 3, lead I'I, re sistance W3, relay An. battery, earth.

Relay P operates in this circuit and opens contact I8p and closes contact I911. Thereupon the following blocking circuit is completed: earth, contacts I30, I9p, winding II of relay P, lead I5, relay G, wiper f of the succeeding switch NW in the normal position; lead I55, wiper c of final selector LWI' on line 3, lead I'I, resistance W3, relay An, battery, earth. With these circuit conditions seizure of the multiply connected characterizing lines I, 2, and 3 by another final selector is prevented. Relay P closes contacts p and 2Ip thereby eiIecting switching through in the final selector LWI. Relay G also operates in the circuit over wiper c of the final selector LWI and by closing contact 22g prepares the test circuit for the allotter V0. Relay G also by closing 23g prepares a circuit over wiper b of the allotter VO.

Relay An also operates in a circuit over wiper c of the final selector LWI and at contact an completes: the following circuit for the driving magnet D of the'allotter V0; earth, contacts 24cm, 25m, driving magnet D0 of the allotter V0, relay interrupter RU2, battery, earth. By means of the relay interrupter RU2 impulses are transmitted to the rotary magnet D0 and the allotter V0 is advanced until the following circuit, which was prepared at contact 22g, is completed over wiper d of the allotter V0, earth, battery, relay P0, wiper d of the allotter V0, contact 22g, relay PV, earth. Relays P0 and PV are energized in this circuit. Relay P0 opens contact 25po which interrupts the circuit of the rotary magnet D0. The following circuit is now completed over wiper b. of the allotter V0; earth, battery, resistance W5, contact 26110, wiper b of the allotter V0, contacts 239, Zip, wiper b of the final selector LWI, lead 2, winding I of relay BZ3, earth. Relay Y is connected in parallel with winding I of relay BZ3. Relay Y, however, cannot operate since relay BZ3 is of low resistance compared with relay Y. Relay BZ3 serves to mark the P. B. X. lines connected to the succeeding switch NW. In the present case only two lines are shown, namely SABI, SA32, which are connected to contacts 2 and 4 of the succeeding switch NW. The marking of these lines is effected by the closing of contacts 212123 and 281723.

After the setting of the allotter V0 the following circuit is completed over wiper c of the allotter V0; earth, relay interrupter RUI, contact 29110, wiper c of the allotter V0, contact 30pnw, relay UNW, rotary magnet DNW of the succeeding switch NW, battery, earth. By means of the relay interrupter RUI, the rotary magnet DNW is operated until a free line in the P. B. X. group is found and thereupon the following circuit is completed: earth, contact 3lpv, relay PNW, contact 32tnw, wiper c of succeeding switch NW on contact 2, night switch NS, contact 2712.23, relay H3 l, wiper c of the preselector VW3 I, relay T3i, battery, earth. Relay PNW operates in this circuit and at contact 3llpnw opens the circuit for the rotary magnet DNW of the succeeding switch NW. Owing to the operation of relay PNW the circuit of relays P0 and PV is maintained independently of contact 229 over contact 35pnw.

During the operation of the relay DNW relay UNW is energized and at contact 341mm maintains the circuit over wiper c of the final selector LWI independently of the normal position of the succeeding switch NW. When the relay UNW releases on completion of the movement of the succeeding switch NW, the circuit over wiper c of the final selector LWI is opened and relays P, G, An and BZ3 release. The marking of the line found free in the P. B. X. group has however been taken over by relay H3| which was energized over wiper 0 since relay H3l maintains the circuit over wiper c at contact 4lh3| independently of contact 211223. After the release of relay UNW on the operation of PNW the following circuit is completed for the rotary magnet DLWI; earth, contact 3613c, wiper a of the allotter V0, contacts 311mm, 38mm, 39tnw, 40a, 8p, rotary magnet DLWI, battery, earth. The rotary magnet advances the final selector LWI one step and also operates contact 901 so that relay U is energized over: earth, off normal contact 2k, contacts 312, 9d, winding II of relay U, battery, earth. Relay U opens the circuit of rotary magnet DLWI at contact 40a andhence contact 9d restores to normal. After .a short interval relay U releases and the circuit for the rotary magnet DLWI is again completed over contact 4011. and the final selector LWI is therefore advanced another step. The rotary magnet DLWI and the relay U interact in this manner until the following circuit is completed over wiper c of the final selector LWI; earth, contacts I30, I40, lu, windings I and II of relay P, wiper c of the final selector LWI in the overflow position ll, lead l6, wiper f of the succeeding switch NW in off normal position, contacts 33mm, lZjp, windings II of relay TNW, battery, earth. Relay P operates in this circuit and by opening contact 8p prevents any further operation of the rotary magnet DLWI. Relay U is not again energized. Relay P closes contact I910 thus maintaining a circuit for itself independent of contacts I42; and [5a. Switching through is again effected by relay P at contacts 20p and 2 ip. Relay TNW operates over wiper c of the final selector LWI and by opening contact 32131110 and closing contact 43tnw interrupts the circuitfor the relay PNW. There is now the following circuit parallel to winding II of relay TNW over wiper c of the succeeding switch NW: earth, contacts I30, I91), winding 11 of relay P, wiper c of final selector LWI in position ll, lead 56, wiper j of succeeding switch NW in off normal position contacts 331mw, 43tnw, wiper c of succeeding switch NW in position 2, night switch NS, contact 4Ih3l, relayH3i, wiper c of switch VWBI in position 0, relay T3I, battery, earth. Since a circuit now exists over winding II of relay TNW and also over contact 43tnw and Wiper c of the succeeding switch NW, seizure of the P. B. X. line SA3I over another succeeding switch is prevented since due to the earth through the low resistance winding of relay P which is now connected to the line of the succeeding switch NW no test circuit can be completed for another succeeding switch. 0n the release of relay PNW the circuit for relays PV and P0 is opened at contact 35pnwand the allotter V0 is therefore released.

The calling subscriber has now been connected to the P. B. X. line SA3 I.

When the called subscriber replaces his receiver at the end of the conversation, the seizing relay C in the final selector LW is released in known manner and by opening contact 13c interrupts the circuit for relays P, TNW, I-l13l and T3| whereupon these relays release. The rotary magnet DNW now receives impulses from the relay interrupter RU over: earth, contacts Mtmu, lfigmw, 46g, wiper e of succeeding switch NW in off normal position, rotary magnet DNW, battery, earth. The rotary magnet DNW now operates the succeeding switch NW until the succeeding switch NW has reached its normal position and hence the above traced circuit over wiper e of the succeeding switch NW is interrupted.

If a subscribed of the P. B. X. is wanted by a toll operator and all the P. B. X. lines accessible over the succeeding switch NW are busy, an existing local connection is broken down and the toll connection is set up in the following manner: The setting of the final selector LWI and of the allotter V0 takes place in the manner already described. Since all the lines of the P. B. X. are busy including both the lines 8A3! and SA32 shown in the drawings, no test circuit can be completed over relay PNW and wiper c of the succeeding switch NW. Accordingly the rotary magnet DNW will advance the succeeding switch NW through positions 2, 3, and 4 and into position 5. In position 5 the following circuit is completed over relay PNW and PP: earth, contact 3ipv, relay PNW, contact 32tnw, wiper c of succeeding switch: in position 5, contact 4111.23, relay FP, battery; earth. Relays PNW and FP:operate. By the opening of contacts Hip and the'closing-of. contact 14817) the high resistance windingv of relay 'I'NW is connected up. Moreoverrelay FPcompletes a locking circuit for themarking relay- BZ3 over: earth, contact 49m, winding II of relay BZ3, battery, earth. As already described the relay PNW brings the succeeding switch NW to rest by the opening of contacttllpnw- Relay UNW and P release and the final selector LWI is set on to the overflow contact Hi When this.:contact is reached the following circuit is completed: earth, contacts I30, I 41),: I514, windings I and 11 of relay P, wiper c offinal selector LWI in position I I, lead I6, wiper f of...succeeding switch NW in off normal position, contact 33mm, windings I andII of relay TNW; battery, earth. Relay TNW operates in this circuit-:but not relay P. Since relay U is onlyr-energizedior a short time and thus opens thecircuit for-relays P. and TNW atcontact .I5u after a short interval, the following circuit is now completed for therrelay' TNW: earth, contact 49th,.thermic relay TH, contacts 50tnw, 48in, windings'I and II' of relay TNW, battery, earth. The toll operatoris given a'busy signalin any desired manner. She thereupon connects battery to the b-lead whereupon relay Y is energized. Relay Y closes contacts My and 52y so that a speaking connection is now completedbetweenthe calling toll operator and the P. B. X. subscriber SA32, since as the succeeding switch NW has been set on to contact'5 there is a connection over the multiple between 4 and 5 with the line SA32 connected to contact 4 ofthe'succeeding switch. Relay TNWisheld over: earth, contacts I30, I81), 51y, winding I and II of relay P,'wiper c of final selector LWI, lead l6, wiper f of succeeding switch NW, contact 33mm, winding I and II of relay TNW, battery, earth.

When the subscriber reached over P. B. X. line SA32 releases his local connection, the blocking of the line reached over contact 4 is removed so that the following circuit is completed for relay WS: earth, contact 53tmo, relay WS, wiper d of succeeding switch NW in position 5, lead 54, contact 281923, relay H32, wiper c of switch VW32in position 0, relay T32, battery, earth. Relay H32 closes contact 5572.32 so that the above circuit is maintained independently of contact 281223. The succeeding switch receives an impulse from the relay interrupter RU over: earth, relay interrupter RU, contact 56108, wiper e of succeeding switch NW in ofi normal position, rotary magnet DNW, battery, earth. The succeeding switch NWtherefore advances to position 6 so that the following test circuit is now completed: earth, contacts I30, I810 51y, windings I and II of relay P, wiper c of final selector LWI in position H, lead l6, wiper of succeeding switch NW in OH normal position, contacts 33mm, 43tnw, wiper c of succeeding switch NW in position 6, lead 58, contact 55h32, relay H32, wiper c of switch VW32, relay T32, battery, earth. Owing to the advance of the succeeding switch from position 5 to position 6 relay FF is released and at contact 491% opens the holding circuit for relay BZ3. Owing to the completion of the test circuit over relay P, this relay efiects switching through so that the toll connection has now been set up.

If all the P. B. X. lines are busy and a local subscriber wishes to set up a connection with a P. B. X. line the circuit operations just described which are initiatedby'relay Y cannot take place since the subscriber has, no means for operating relay Y in the final selector. Hence when the succeeding switch NW reaches position 5 owing to the group of P. B. X lines being busy, relay FP operates but no test and holding circuit for relay TNW can be set up over relay P since this can only extend over contact 51y. As already described however, relay FP at contact 48 10 completes the circuit for relay TNW and the thermic relay TH which becomes operative after a short interval, and by opening contact 49th opens the circuit for the relay TNW. The rotary magnet DNW is operated over contact Mtnw and hence the succeeding switch is restored to its normal position.

In order that during the night-time a calling subscriber shall only be connected with a particular line of the P. B. X. group, the operator before she leaves her position throws the night switch NS whereupon all the lines of the group except a single one, in the present case line SA32 are marked Engaged. The night call number is notified to the subscribers. If during the night-time the subscriber wishes to set up a connection over the group of P. B. X. lines with a trunk operator, he can only be connected to the particular line of the P. B. X. group and since this line is known to him-,he can'give the trunk operator the number of the line used in order that she may call back.

If the group of P. B. X. lines, which in the present case comprises only lines SASI and SA32, is for instance to be extended, i. e. an additional line is to be added, it is only necessary to connect this line to-any free contact of the succeeding switch NW without in any way altering the operation of the final selector LWI or making any changes in'the multiple of this switch.

Havingdescribed the invention, what is considered'to be new and is desired to be protected by Letters Patent will be set forth in the following claims.

What is claimed is:

1. In an automatic telephone system, an automatic switch, an auxiliary switch accessible to said automatic switch, a plurality of lines directly accessible to said auxiliary switch, means for operating said automatic switch to a position correspondingjto one of the lines of said auxiliary sw1tch,.means responsive thereto for operating said auxiliary switch to select and connect with one of said lines,-.:and means for reoperating said automatic switch to connect with said auxiliary switch.

2. In anautomatic telephone system, an automatic switch, an auxiliary switch accessible to said automatic switch, a plurality of groups of lines directly accessible to said auxiliary switch, means for operating said automatic switch to a position correspondingto one of said groups of lines, means respcnsive'th'ereto for operating said auxiliary switch to select and connect with an idle one of said selected group of lines, and means for then reoperating said automatic switch to connect with said selected line through said auxiliary switch.

3. In an automaticv telephone system, a plurality of automatic switches havingwipers, an auxiliary switch for each of said automatic switches'and accessible thereto, wipers for each auxiliary switch, a plurality of. groups of lines accessible to the. wipers of each auxiliary switch, meansifor selecting an idle one of said automatic switches. andoperatingit: to a position. in accordance with a particular group of lines, means responsive thereto for operating the auxiliary switch associated with the selected automatic switch to select an idle one of the lines in the group selected, means for again operating said automatic switch to connect its Wipers with the wipers of its operated auxiliary switch and extend the connection through said automatic and auxiliary switches to said selected line.

4. In an automatic telephone system, a plurality of automatic switches, an auxiliary switch individual to and accessible to each automatic switch, wipers for said auxiliary switch, groups of lines accessible to the wipers of each auxiliary switch, a marking line for each group of lines accessible to said automatic switch, means for operating one of said automatic switches to connect with a marking line of a particular group of lines, a call allotter common to said automatic switches for controlling the auxiliary switch of the operated automatic switch to select and connect with an idle one of said selected group of lines over its wipers and for reoperating said automatic switch from its position on said marking line to connect with the wipers of its auxiliary switch and complete the connection through said wipers to the selected line.

5. In an automatic telephone system, automatic switches, an auxiliary switch associated with each automatic switch having wipers, a plurality of groups of lines accessible to said auxiliary switch through its wipers, marking lines each corresponding to a particular group of lines accessible to said automatic switches, said auxiliary switch connected to bank contacts located in a position following the marking line contacts in the bank of said automatic switch, means for operating an automatic switch to a position to connect with one of said marking lines, and an allotter switch common to said automatic switches operated to control said auxiliary switch to select an idle one of the lines of the marked group to connect its wipers thereto and for then operating said automatic switch to a position to connect with the selected idle line through the wipers of its aux iliary switch.

6. In an automatic telephone system, an automatic switch having wipers, an auxiliary switch accessible to said automatic switch through its wipers, a plurality of groups of lines accessible to said auxiliary switch, means for operating said automatic switch for a local connection to mark a particular group of said lines, means for operating said auxiliary switch to select one of an idle line of the selected group and extend a connection thereto, and means for reoperating said auxiliary switch for a toll connection in case all of said lines are busy to operate said auxiliary switch to extend a connection to said busy line.

FRITZ LUBBERGER. 

